Javascript动态函数调用

function sayHello() {
  console.log("Hello!");
}

function sayWorld() {
  console.log("World!");
}

const functionName = "sayHello";
window[functionName](); // 输出 "Hello!"

const calculator = {
  add: function (a, b) {
    return a + b;
  },
  subtract: function (a, b) {
    return a - b;
  },
};

const operation = "add";
console.log(calculator[operation](2, 3)); // 输出 5

function sayHello() {
  console.log("Hello!");
}

function sayWorld() {
  console.log("World!");
}

const functions = [sayHello, sayWorld];
functions[0](); // 输出 "Hello!"